16beta-amino-3beta, 17alpha-dihydroxypregn-5-en-20-one 20-ketals and acyl derivatives thereof



United States Patent ABSTRACT OF THE DISCLOSURE 16B-amino-3fl,17u-dihydroxypregn 5 en -one 20- ketals and acyl derivatives thereof useful as pharmacological agents, as exemplified by their central nervous system-stimulant, anti-depressant, hypotensive, analgesic, pepsin-inhibitory, anti-ulcerogenic, anti-bradykinin, antiinflammatory, anti-bacterial, anti-protozoa], anti-fungal, anti-algal and dicotyledonous seed germination-inhibitory activity. These com-pounds are prepared by reaction of the corresponding 16a,17u-epoxide with the appropriate amine or, alternatively, by acylation of the amino function followed by reduction of the amide moiety.

The present invention is concerned with novel steroidal derivatives characterized by l6/3-amino and ZO-ketal functions and, more particularly, with 16B-amino-3/i,l7adihydroxypregn-S-en-ZO-one 20-ketals and acyl derivatives thereof represented by the following structural formula wherein R is hydrogen or a lower alkanoyl or (lower alkoxy)carbonyl radical, R and R can be hydrogen or a lower alkyl, lower alkynyl, lower alkenyl, lower cycloalkyl or hydroxy(lower alkyl) radical or R or R" together with the nitrogen atom comprise a secondary heterocycloaliphaticamino radical and n is a positive integer greater than 1 and less than 4.

The lower alkyl radicals symbolized by R and R in the foregoing structural representation are typified by methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and the branched-chain radicals thereof.

The term lower alkoxy embraces radicals of the formula -O- (lower alkyl) while the term lower alkanoyl comprehends radicals of the formula n -O 0- (lower alkyl) wherein the lower alkyl radicals are as hereinbefore defined.

Examples of the lower alkenyl radicals denoted in that formula are allyl, propenyl and butenyl while the lower alkynyl radicals are typified by propargyl, butynyl, etc.

The heterocycloaliphaticamino radicals indicated in that formula are, for example pyrrolidino, piperidino,

3,378,551 Patented Apr. 16, 1968 morpholino, pipecolino, piperazino, N-alkylpiperazino, trimethylenimino, hexamethylenimino, aziridino, etc.

The term lower cycloalkyl includes, for example, cyclopentyl, cyclohexyl, etc.

The novel compounds of the present invention are conveniently manufactured by processes which utilize as starting materials 16a,17a-epoxides of the following structural formula wherein R and n are as hereinbefore defined. When those materials are contacted with the appropriate amine reactant, the instant l6fl-amino-l7a-hydroxy derivatives are produced. A specific example is the reaction of 3B-acetoxy- 16a,l7u-epoxypregn-5-en-20-one ZO-ethylene ketal with methylamine, thus affording 3B,17a-dihydroxy-16fi-methylaminopregn-S-en-ZO-one ZO-ethylene ketal.

A convenient method for production of the N,N-di alkyl compounds of this invention involves the consecutive steps of acylation of the corresponding N-monoalkyl substances with a lower alkanoic acid anhydride or lower alkyl chloroformate and reduction of the resulting amido product. This two-step process is specifically exemplified by the reaction of 3,8,l7adihydroxy-lfifi-methylaminopregn-S-en-ZO-one ZO-ethylene ketal with acetic anhydride in pyridine to yield 3/3-acetoxy-l7a-hydroxy-16B- methylacetamidopregn-S en 20 one ZO-ethylene ketal, which is contacted with lithium aluminum hydride in tetrahydrofuran to produce 3fi,17u-dihydroxy-16,8-N-ethyl-N-rnethylaminopregn-S-en-ZO-one 20-ethylene ketal. The use of an alkyl chloroformate is exemplified by the reaction of 3,8,l7a-dihydroxy-16fl-methylaminopregn- S-en-ZO-one 20ethylene ketal with ethyl chloroformate in pyridine to afford l-N-methy1ethoxycarbonylamido- 3,8-ethoxycarbonyloxy-l7a-hydroxypregn-S-en-ZO-one 20- ethylene ketal. Reduction of that urethan, similarly with lithium aluminum hydride in tetrahydrofuran, results in 3,8,17a-dihydroxy-l6p-dimethylaminopregn S-en-ZO-one ZG-ethylene keta'l.

Equivalent to the organic bases of this invention are the corresponding non-toxic acid and quaternary salts, for example the citrate, tartrate, .rnaleate, ascorbate, gluconate, lactate, succinate, phosphate, sulfate hydrobromide, hydrochloride, methiodide, etbiodide, methochloride, methobromide, methosulfate, and ethosulfate.

The instant compounds display valuable pharmacological properties. They are central nervous system-affective agents, for example, as is evidenced by their stimulant, antidepressant and analgesic activity. They are 'antiinfiammatory agents also in consequence of their ability to inhibit the edema and granuloma formation associated with inflammatory states. In addition, they exhibit hypotensive, pepsin-inhibitory, anti-ulcerogenic and anti bradykinin properties. These compounds are, moreover, anti-microbial agents as is evidenced by their ability to inhibit the growth of bacteria such as Bacillus sublz'lis, protozoa such as Tetrahymcna gelleii, algae such as Chlorella vulgaris and fungi such as Candida albicans. They inhibit also the germination of dicotyledonous seeds.

These substances can be administered in any of a number of conventional pharmaceutical forms and also by conventional routes. For oral administration suitable solid forms are pills, powders, capsules, tablets, and the like and suitable liquid forms are syrups, emulsions, elixers, suspensions and the like. For parenteral administration these compounds can be dispersed in an aqueous suspension or dissolved in a pharmacologically acceptable oil or oil-water emulsion. Suitable excipients can also be added.

The pharmacological activity of the novel compounds of this invention is specifically illustrated by the anti-inflammatory activity of 3/3,17a-dihydroxy-l6 8-methylaminopregn-S-en-ZO-one ZO-ethylene ketal, 3B,17a-dihydroxy-l6B-morpholinopregn-5-en-20-one ZO-ethylene ketal and 3 8,l7ot-dihydroxy-16fl-dimethylaminopregn-5-en-20- one 20-ethylene ketal. These compounds were assayed in the rat at intragastrically administered doses of 25, 20 and 1-5 mg. per day, respectively, for two successive days and were found effective in inhibiting the granuloma formation induced by the subcutaneous implantation of cotton wads.

The specific assay used is a modification of that disclosed by Dulin, Proc. Soc. Exp. Biol. Med, 90, 115 (1955) and is described as follows:

Male rats weighing 180-220 g. are adrenalectomized and arranged into groups of six animals each. The animals are maintained on 0.86% saline drinking water for the duration of the test and are supplemented with 5% aqueous glucose for the first 24 hours following andrenalectomy. On the day following the operation, 4 cotton dental pellets, with an average weight of approximately 6 mg, are individually implanted in a bilateral position in the pectoral and dorsal lateral neck regions of each rat. The test compound, dissolved or suspended in a saline-wetting agent mixture or in corn oil, is administered, by stomach tube on the day of the pellet implantation and the treatment is repeated on the following day. On the day following the last treatment the rats are sacrificed and the pellets with associated granuloma tissue are carefully dissected, dried and weighed. These weights are compared with those from a group of control animals concurrently treated as above save for omission of the test compound. The test compound is rated active if it causes a significant decrease (P 0.05) in the weight of encapsulated tissue surrounding the cotton pellets.

The invention will appear more fully from the examples which follow. These examples are set forth by way of illustration only and it will be understood that the invention is not to be construed as limited either in spirit or scope by the details contained therein as many modifications both in materials and methods will be apparent from this disclosure to those skilled in the art. In these examples temperatures are given in degrees Centigrade C.). Quantities are expressed in parts by weight unless otherwise noted.

EXAMPLE 1 A container containing 50 parts of 3fi-acetoxy-l6u,l7otepoxypregn-S-en-ZO-one 20-ethylene ketal is cooled to approximately -70 and 300 parts of liquid methylamine is added. The container is sealed and heated at 140-145 at an internal pressure of 830890 pounds per square inch for about 10 days. At the end of that reaction time the mixture is cooled and removed from the container with the aid of ethanol. The resulting slurry is evaporated to dryness and the residue obtained is recrystallized from acetone-hexane to yield pure 3B,17a-dihydroxy- 16fl-methylarninopregn 5-en-20-one 20-ethylene ketal, melting at about 181.5-191. The material obtained by concentration to dryness of the mother liquor is again recrystallized from acetone-hexane to yield additional product, melting at about 181491". The product of this example is represented by the following structural formula EXAMPLE 2 When an equivalent quantity of ethylamine is substituted in the procedure of Example 1, there is produced 165 ethylamino-3/8,17a-dihydroxypregn-S-en-Z0-one 20- ethylene ketal.

EXAMPLE 3 A mixture of 20 parts of 3 3-acetoxy-l6a,17a-epoxypregn-S-en-ZO-one 20-ethylene ketal and 200 parts of morpholine is heated in a closed container at 175185 for about 5 days. The container is then cooled to room temperature and the contents are removed with the aid of fresh morpholine. The resulting pale brown solution is filtered and the filtrate is concentrated at reduced pressure to afford a brown syrupy material. Crystallization of that material from aqueous methanol affords the crude product, melting at about 112-115". Further purification is effected by an additional recrystallization from aqueous methanol, thus affording pure 318,17a dihydroxy-lpmorpholinopregn 5 en-20-one 20-ethylene ketal, which melts at about 114-1175 and is represented by the following structural formula O-CHz C CH OCH2 EXAMPLE 4 By substituting an equivalent quantity of pyrrolidine in the procedure of Example 3, there is produced 313,170:- dihydroxy-16fl-pyrrolidinopregn-5-en-20one 20 ethylene ketal.

EXAMPLE 5 The substitution of an equivalent quantity of piperidine in the procedure of Example 3 results in 36,17o-dihydroxy-16fi-piperidinopregn-5-en-20-one 20-ethylene ketal.

EXAMPLE 6 To a mixture of 20 parts of 3B-acetoxy-16a,17a-epoxypregn-S-en-ZO-one 20-ethylene ketal with 200 parts by volume of dimethyl sulfoxide, cooled to approximately is added parts of liquid ammonia and the resulting mixture is heated in a sealed container at approximately and 1200 pounds per square inch pressure for about 5 days. At the end of that time the reaction mixture is cooled and the resulting slurry containing white crystals is poured into approximately 3,000 parts of water. That aqueous mixture is stirred for about 30 minutes and the resulting crude product is collected by filtration. That material, melting at about 149.5194.5, is recrystallized from aqueous methanol containing decolorizing carbon to afiord the purified product, melting at about 85-1915 That crude product is partitioned between ethyl acetate and dilute hydrochloric acid. The aqueous phase is separated, neutralized with dilute aqueous sodium hydroxide and filteredin order to isolate the resulting solid crude product. Recrystallization of the latter material several times from aqueous methanol yields pure 16/8-amino- 3,8,17u dihydroxypregn 5 en-ZO-one -ethylene ketal, which melts at about 210.5-2195" and is represented by the following structural formula When a solution of the latter amine in ether is mixed with excess isopropanolic hydrogen chloride, there is produced a precipitate, which is purified by recrystallization from methanol-ether to yield l6/8-amino-3B,17otdihydroxypregn-S-en-ZO-one ZO-ethylene ketal hydrochloride hemihydrat e, which melts at about 249250 with decomposition.

,EXAMPLE 7 To a solution of 3.83 parts of 3;8,17a-dihydroxy-16fimethylaminopregn-S-en-20-one 20-ethylene ketal in 38 parts of pyridine is added dropwise 4.3 parts 'of ethyl chloroformate. The mixture is externally cooled during the addition in order to control the violent reaction. The reaction mixture is then diluted with approximately 400 parts of Wate and the resulting yellow suspension is cooled at 0-5 in order to promote crystallization of the product. The yellow solid material thus produced is collected by filtration and recrystallized three times from aqueous acetone to afford pure 16B-N-methylethoxycarbonylamido 3 3-ethoxycarbonyloxy-17a-hydroxypregn-5- en-20-one 20-ethylene ketal, melting at about 170174.5 and represented by the following structural formula I I O-CHz EXAMPLE 8 NC-O CHzCHa 6 EXAMPLE 9 O-CHz NCOCHa EXAMPLE 10 By substituting an equivalent quantity of propionic anhydride and otherwise proceeding according to the processes described in Example 9, there is obtained 17OL-hydroxy-16B-N-methylpropionamido 3 (3 propionoxypregn- 5-en-20-one' 20-ethylene ketal.

EXAMPLE 11 To a mixture of 1 part of lithium aluminum hydride with parts of tetrahydrofuran is added cautiously 3.3 parts of 3;8-acetoxy-17a-hydroxy-16,3-N-methylacetamidopregn-S-en-ZO-one ZO-ethylene ketal, and the resulting reaction mixture is heated at the reflux temperature with stirring for approximately 72 hours. At the end of that time, 80 parts of ethyl acetate is added over a period of about 30 minutes in order to destroy the excess reagent. Saturated aqueous sodium potassium tartrate in the amount of 50 parts by volume is then added and the resulting two phase system is separated. The organic layer is dried over anhydrous sodium sulfate and stripped of solvent by distillation under reduced pressure. The resulting residue is mixed with 7 parts of pyridine and 3.5 parts of acetic anhydride, and that mixture is allowed to stand at room temperature for approximately 24 hours. Precipitation of the acetylated product by dilution with water affords an aqueous suspension, which is extracted with toluene. The organic extract is dried over anhydrous sodium sulfate, then concentrated to dryness under reduced pressure. The remaining solid is dissolved in approximately parts of ether and that organic solution is made acidic by the addition of approximately 15 parts by volume of l N hydrochloric acid. The white precipitate is' isolated by filtration, then dissolved in approximately 20 parts of methanol and that organic solution is made alkaline by the addition of approximately 10 parts by volume of 10% aqueous sodium hydroxide, then diluted to a total volume of 250 parts with water. Filtration of the mixture affords a crystalline product, which is purified by means of consecutive recrystallization from aqueous methanol, thus producing pure 3fi,17a-dihydroxy-16B-N- ethyl-N-methylaminopregn-S-en-ZO-one 20-ethylene ketal,

I? Ii melting at about 1445-1485". It is represented by the following structural formula OC1Iz EXAMPLE 12 When an equivalent quantity of 17oc-hYdIOXY-l6B-N- methylpropionamido 3,6 propionoxypregn-S-en-ZO-one ZO-ethylene ketal is substituted in the procedure of Example 11, there is produced 3,8,17a-dihydroxy-16fi-N-npropyl-N-methylaminopregn en-ZO-one ZO-ethylene ketal.

EXAMPLE 13 To a reaction vessel containing 540 parts of tetrahydrofuran is added successively with stirring, while a stream of nitrogen is passed into the reactor, 7.14 parts of lithium aluminum hydride, 7.14 parts of 16(3-N-methylethoxycar-bonylamido 3,8 ethoxycarbonyloxy-17m-hydroxypregn-S-en-ZO-one ZO-ethylene ketal and 108 parts of tetrahydrofuran. The resulting reaction mixture is heated at the reflux temperature for about 72 hours, at the end of which time approximately 40 parts of ethyl acetate is added in order to destroy the excess reagent. Approximately 100 parts by volume of saturated aqueous sodium potassium tartrate is then added over a period of minutes, resulting in a two-phase system. The organic layer is separated by decantation, then is dried over anhydrous sodium sulfate and stripped of solvent by distillation under reduced pressure. The resulting residue is partitioned between ether and dilute hydrochloric acid, and the white pasty solid which forms is shaken with dilute aqueous sodium hydroxide, then recrystallized from aqueous methanol to afford 36,17a-dihydroxy 16;? dimethylaminopregn-S-en-ZO-one -ethylene ketal, melting at about 149.5-163". Additional product, melting at about 150 161.5 is obtained by recrystallization from aqueous methanol of the fraction obtained from the mother liquor.

The product of this example is represented by the following structural formula CIIa EXAMPLE 14 When an equivalent quantity of 16/3-ethylamino-3 5,170:- dihydroxypregn-S-en-20-one 20-etl1ylene ketal is substituted in the procedure of Example 9, there is produced 3,8 acetoxy 16/3 N ethylacetamido 17a hydroxypregn-S-en-ZO-one ZO-ethylene ketal.

By substituting an equivalent quantity of 3,8-acetoxy- 16,8 N ethylacetamido 17cc hydroxypregn 5 en- 20one ZO-ethylene ketal and otherwise proceeding ac- 3 cording to the processes described in Example 11, there is produced 16B-diethylamino-3/3,l7a-dihydroxypregn-5- en-ZO-one 20-ethylene ketal.

EXAMPLE 15 A pale yellow solution containing 1 part of 3fl-acetoxy- 16a,17u epoxypregn 5 en 20 one 20-ethylene ketal and 25.5 parts of ethanolamine is heated at the reflux temperature for about 19 hours, then is concentrated to dryness by distillation under reduced pressure. The residual cream colored solid is slurried with water and collected by filtration. That crude product, melting at about 179, is purified by recrystallization from acetonehexane to afford crystals of pure 3/3,17a-dihydr0xy-16,9- (Z-hydroxyethyl)aminopregn-S-en-ZO-one ZO-ethylene ketal, melting at about 178-188. This compound is represented by the following structural formula CH l O-GHz O-GHz CH3 on NCIIZCHZQH EXAMPLE 16 When an equivalent quantity of 3-hydroxypropylamine is substituted in the procedure of Example 15, there is produced 3,8,170: dihydroxy 16B (3 hydroxypropyl) aminopregn-S-en-ZO-one ZO-ethylene ketal.

What is claimed is:

1. A compound of the formula O-GHz wherein R is selected from the group consisting of hydrogen and lower alkanoyl and (lower alkoxy)carbonyl radicals, R and R" are members of the class consisting of hydrogen, lower alkyl, lower alkanoyl, hydroxy(lower alkyl) and (lower alkoxy)carbonyl radicals or R and R together with the nitrogen atom comprise a secondary heterocycloaliphaticamino radical.

2. As in claim 1, a compound of the formula CH; O-CH1 wherein I O-CH:

wherein R and R" are selected from the group consisting of hydrogen and lower alkyl radicals.

4. As in claim 1, a compound of the formula O-CH:

N(lower alkyl);

10 5. As in claim 1, a compound of the formula CH3 i/o-cm l OCH2 CH3 OH i TNHflower alkyl) l 6. As in claim 1, the compound which is 3fi,l7a-dihydroxy-16p-methylaminopregn-5-en-20-one 20-ethylene ke tal.

7. As in claim 1, the compound which is 318,17a-hydroxy-l6B-morpholinopregn-5-en-20-one 2'0-ethylene ketal.

8. As in claim 1, the compound which is 16,8-arnino- 3,8,l7a-dihydroxypregn-5-en-20-0ne 20-ethylene ketal.

9. As in claim 1, the compound which is 3,8,l7a-dihydroxy-l6/3-dimethylaminopregn-S-en-ZO-one 20 ethylene ketal.

10. As in claim 1, the compound which is 3fl-acetoxy- 17oz. hydroxy 16B N methylacetamidopregn 5 en- 20-one ZO-ethylene ketal.

11. As in claim 1, the compound which is 16B-N- methylethoxycarbonylamido 313 ethoxycarbonyloxy- 17u-l1ydroxypregn-5-en-20-one ZO-ethylcne ketal.

References Cited UNITED STATES PATENTS 3,232,930 2/1966 Bergstrom 260239.5

LEWIS GOTTS, Primary Examiner.

E. G. LOVE, Assistant Examiner. 

